Description

In short:
When I shutdown system or execute: /etc/init.d/vboxdrv stop
I got:
kernel:[ 2157.199178] unregister_netdevice: waiting for vboxnet1 to become free. Usage count = -2

In dmesg also there is: dev_remove_pack: ffff8802100c10d8 not found.

Current vbox version: 4.1.16, but this problem started before.
I thought it started when I updated kernel, because normally I do not update vbox often, but in bugzilla.redhat.com, where I opened bug about this problem, I got suggestion that this is problem with vbox, and I should write there.

Starting with Linux kernel 3.2.18 notification handler gets called for all devices when this handler is being unregistered. This caused vboxnetflt to decrease twice the reference count of the device it was attached to.